Harmonic reducer makes a flexible wheel generate controllable elastic deformation by a wave generator, and uses a controllable elastic deformation of a flexible bearing to transmit motion and power. As a reducer with high reduction ratio, small mass, light weight and high transmission precision, the harmonic reducer is recognized as the “best” transmission gear for robots, and is widely applied to various fields of transmission systems, such as spacecraft, spaceship, robot, radar equipment and medical equipment.
At present, China is vigorously developing high-end intelligent equipment industry represented by robots. Since 2013, China has become the largest market for industrial robots in the world for three consecutive years. China is gradually entering the stage of development of industrialization for the industrial robots. In the process of industrialization for the industrial robots, however, there are many puzzles that hinder the development. Among them, the status quo that core components represented by precision reducers cannot be self-sufficient is particularly prominent.
Precision flexible thin-wall bearing is a core component of the harmonic reducer and plays a vital role in an overall performance of the harmonic reducer. Under working condition, the precision flexible thin-wall bearing is not only subjected to elastic deformation under extrude-bulge of an inner ring of the thin-wall bearing precisely matching with an elliptical axis, but also subjected to an alternating stress generated by its own operation, and in the case of unsatisfactory working conditions, the precision flexible thin-wall bearing is also subjected to different static or dynamic loads from the outside world. Therefore, in the research and development process of the flexible thin-wall bearing used for the harmonic reducer, stability, rotation precision and life of the precision flexible thin-wall bearing should be tested. Only after all the performances meet requirements can the industrial production be put into operation, thereby solving a bottleneck problem of the core component of the industrial robots in China, providing support for the industrialization and wide application of the industrial robots in China. However, there are very few reports on the flexible thin-wall bearing, a life testing machine thereof and a flexible thin wall fault diagnosis method at home and abroad.
As a key component of the harmonic reducer, the rotation precision and stability of the precision flexible thin-wall bearing under different working conditions plays a very important role in the overall performance of the harmonic reducer. A geometric cross-sectional shape of the precision flexible thin-wall bearing is circular, and becomes elliptical when loaded in the harmonic reducer. Thus, the development of the fault diagnosis and life testing machine for the precision flexible thin-wall bearing used for the harmonic reducer should simulate the life testing of the flexible thin-wall bearing under actual working conditions as much as possible.